Abstract: A method and apparatus for sealing a wellbore is described herein. A convertible seal includes a sealing element and a valve. The sealing element is in fluid communication with the valve and fluidly blocks a bore of the convertible seal. The sealing element prevents fluid from flowing through the bore until desired. When desired, the sealing element is removed to allow fluid to flow through the bore. Fluid flow in the bore is controlled by the valve. As a result, the convertible seal has been converted to a flow control seal.

Abstract: A method and apparatus for sealing a wellbore is described herein. A convertible seal includes a sealing element and a valve. The sealing element is in fluid communication with the valve and fluidly blocks a bore of the convertible seal. The sealing element prevents fluid from flowing through the bore until desired. When desired, the sealing element is removed to allow fluid to flow through the bore. Fluid flow in the bore is controlled by the valve. As a result, the convertible seal has been converted to a flow control seal.

Abstract: A method and apparatus for sealing a wellbore is described herein. A convertible seal includes a sealing element and a valve. The sealing element is in fluid communication with the valve and fluidly blocks a bore of the convertible seal. The sealing element prevents fluid from flowing through the bore until desired. When desired, the sealing element is removed to allow fluid to flow through the bore. Fluid flow in the bore is controlled by the valve. As a result, the convertible seal has been converted to a flow control seal.

Abstract: A system for facilitating the insertion of a tool into a wellbore, especially a non-vertical wellbore. In one embodiment a tool is fixable in a wellbore and includes centralizing, friction-reducing members that serve to keep the body of the tool off the walls of the wellbore. In another embodiment the tool includes a wiper ring that partially fills an annular area formed between the centered tool and the wellbore walls. The surface of the ring facing the upper end of the wellbore provides fluid resisting piston surface and permits the centered tool to be pumped down the wellbore more effectively.

Abstract: A method and apparatus for sealing a wellbore is described herein. A convertible seal includes a sealing element and a valve. The sealing element is in fluid communication with the valve and fluidly blocks a bore of the convertible seal. The sealing element prevents fluid from flowing through the bore until desired. When desired, the sealing element is removed to allow fluid to flow through the bore. Fluid flow in the bore is controlled by the valve. As a result, the convertible seal has been converted to a flow control seal.